Electric-energy-translation system



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Original Filed Dec 12, 1923 A G LANDEEN ELECTRIC ENERGY TRANSLATION SYSTEM Nov. 8, 1927.

lnvenfar flrwbf Landeen Nov. 8, 1927.

A. G. LANDEEN Original il 1923 ELECTRIC ENERGY TRANSLATIO SYSTEM 2 Sheets-Sheet 2 WGUMEW Arr/'0 6 Landeen lnyenfar Patented Nov. 8, 1927.

UNITED STATES PATENT OFFICE.

ARVID G. LANDEEN, 0F CALDWELL, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK...

ELECTRIO-ENERGY-TRANSLATION SYSTEM.

Application filed December 12, 1923, Serial No. 680,167. Renewed November 30, 1926.-

This invention relates to electric energy translation systems.

An object of the invention is to translate electric energy as a means of signaling.

Another object of the invention is to utilize alternating currents as power supply sources in electric wave transmission systems and to reduce the detrimental effects of ripples resulting from the rectification of the alternating currents.

A further object of this invention is to rectify alternating currents and to suppress pulsations or ripples remaining in the rectified current.

A more specific object of the invention is to utilize polyphase alternating currents as sources of space current, filament heating current and grid potential in a vacuum tube modulating system.

Another object of the invention is to utilize two-phase power as a source of supply of energy for a vacuum tube modulating system and to suppress ripples resulting therefrom.

A feature of the invention relates to a vacuum tube modulator supplied with power from a polyphase source by means of balanced rectifier-s having means for suppressing ripples in the rectified current.

Another feature of the invention relates to means connected to the grid electrodes of vacuum tube rectifiers for impressing thereon potentials varying at the frequency of ripples in the rectified current but in out of phase relation thereto-'whereby the rip ples are substantially eliminated.

Another feature of the invention relates to a vacuum tube oscillator supplied with power from a rectifier connected to an alternating current source which oscillator has a variable grid leak arranged to suppress ripples in the current supply by varying the grid potential of the oscillator in the proper manner.

This invention may be embodied in a modulating system comprising a source of signals, a source of high frequency oscillations, and a modulator. 'The modulator is interposed between the signal source and source of oscillation and is supplied with power from a source of two-phase alternating current. It comprises pairs of vacuum tubes symmetrically connected to the source of current. This modulator acts as a rectifier and supplies two-phase current to the oscillator and to a speech amplifier connected to a transmitter constituting the source of signals. The speech amplifier acts under the control of the transmitter to vary the grid potential of the modulator tubes and thus causes variations in the potential of the rectified current supplied to the oscillator in a manner well known. An antenna is coupled to a tuned circuit in the oscillator for radiating speech modulated energy.

Various means are provided to suppress ripples in the rectified current, for example, by impressing potentials on the rectifier grids in out of phase relation to the rip 'ple components or by providing tuned circuits for offering high impedance to the ripple frequency In one instance a transformer has its primary winding arranged to receive current of the ripple frequency and its secondary connected to impress potentials varying "at this, frequency on the grids of the rectifier tubes at a phase 180 from that of the ripples in the rectified current whereby they are suppressed.

Current from the rectifier-modulator is also used to produce the proper polarizing potential upon the grid electrodes of the speech amplifier and the modulator tubes. The filaments of all the tubes of the system are heated from the same source of alternating current. No batteries are required in the system other than that used to supply energy to the transmitter.

Various embodiments of this invention are illustrated in the drawings to wit:

Fig. 1, a radio transmitting system utilizing two-phase rectified current with means for suppressing ripples in the rectified current.

Fig. 2, circuit modifications that may be ilubstituted for corresponding portions of Fig. 3, an amplifier which may be incorporated in the circuit of Fig. 1 for suppressing ripples.

Fig. 4, a modification of the rectifier filament heating circuit of Fig. 1.

In the drawings like reference'characters have been used throughout the various figures to indicate similar parts.

The modulating system of Fig. 1 comprises a microphone 10, which typifies any source of speech frequency waves, a speech frequency amplifier 20, a rectifier modulator 30, an oscillator 40, and an antenna 45. Connected in series with the microphon is a battery ll, and 12 of transformer 13.

An output circuit of amplifier L0 is connected bet-ween its filament and plate ant. may be traced from the plate ot ti Jrimar 1 through the space current paths of tubes 3h 32, ll and 42 in parallel to the secondary windings 33 and l3 of alternating current power transformers 3 1- and ist, resistance 35, divided resistance l6, to the filament of tube 10. A. condenser 3'? is connected between the plate and filament of tube to supply a path in shunt to the space current supply circuit of the tube for the varying or alternating current components.

The filament of tube 15 is supplied with heating current by a transformer 38. The primary winding 39 of the transformer is connected to terminals 18 and 36 arranged to be connected to one-phase of a source of two-phase alternating current. The sec ondary winding a5 is connected in series with the filament of tube 15. Resistance 4L6 connected in shunt to the winding and ha." a mid tap whereby the input and outau circuits of the tube may be connected to a point which has the same alternating potential as the midpoint of the filament.

Rectifier modulator 30 comprises two pairs of vacuum tubes 31, 32, ll and 41-2. Tubes 31 and 32 have their plate electrodes connected to opposite terminals of the secondary winding of transformer 3 whereas tubes 41 and 42 have their plate electrodes connected to opposite terminals of the primary winding 43 of transformer Primary 37 of transformer 3d connects to one phase of the source of two phase alternating current, whereas primary winding l? of transformer 44: is connected to the second phase of the same source of current. The midpoint of secondaries 33 and 43 connect to a common output circuit. The res cctiye halves of each Winding are shunted by con densers designed to offer high impedance to current from the power source but to offer low impedance to currents within the range of frequency of the signals.

The filaments of tubes 31. 32 are connected. in parallel to the terminals of so"- ondary winding 51 of transformer 4; the primary winding 49 of which is connected in parallel with the primaries 39 and 37 to the one phase of the source of two phase alternating rerzeee current. The filaments of tubes ll and 412 1/0 to L113 second the source of alternating current. inc rids of tubes 31, 32, -11 and 42 are all connected t This common input circuit. circuit may be traced from the grids of these tubes secondary winding of transformer 18 in parallel. with resistance 53; secondat l whirling of transformer in parallel with resistance the portion of resistance 57 shunted by condenser 61, divided resistances 62 a -d 33 in parallel to the filaments of tubes 31, 32, 43:1 and 4-2.

As a means of impressing potentials of the r'pple frequencies on the grids of the rectifier modulator tubes, the primary winding of transrc'mer is connected between condensers 65 and 86 across the common output circuit of the rectifier tubes. The condensers permit the passage of alternating current but prwent the passage of direct current.

, oscillator comprises a vacuum tube an input circuit connected across cone input prises a grid leal: resistance 69 and a choke coil 70 in series with. the divided resistance ii. The latter is in shunt to "he secondary winding of transformer 93 y i plies heatii'lg current to the lilaineut. The output circuit of be (33 may be traced as follows: plate of tube cs, choke coil l2, resistance 62 and (53 in parallel through the filament plate paths of tubes ll and 42 in parallel to branch circuits through the secondary windings 33 and of transi rmers 3-iand il iresonant circuit '73, resistance 71 to the filament of tube 68. A switch 7. 1; is provided for short circuiting the resonant circuit 73. A series resonant circuit comprising an inductance 75 and a variable comlenser 77 in series is connected in shunt to a portion of the output circuit by means of the switch 73. The function these resonant circuits is to aid in supprcising the ripples in the rectified current in a manner which will be explained more fully later.

The oscillator a0 has a resonant circuit 79 connected between the input and output circuits of tube (58 and in series therewith on the plate side of the tube is the condenser 80 and on the grid side of the tube resistance 31 and a condenser 82. The resonant circuit 79 comprises a variable condenser 83 and an inductance The mid point of the latter is connected to the filament of tube 68 through the rcsisistance 71. The inductance 84a is coupled to the inductance coil 86 connected between the aerial 45 and ground.

Ill)

In the operation of the system of Fig. 1, two phase alternating current applied to the primary windings of transformers 34 and 44 is rectified by means of tubes 31, 32, -ll and This rectified current is applied to the output circuit of amplifier 20 and to the plate circuit of oscillator 40.

It is found that there are ordinarily present, in. the rectified current, variations of relatively small amplitude, which are termed ripples, and which have frequencies that are harmonics of the frequency of the alternatingr current connected to the transformers i134. and 4-4. these harmonics the fourth, is perhaps the most pronounced. In order to eli .iinate the ripples, this system provides an lll'tl-Q'QFOIlF-Jli circuit 73 connected in series with. the output circiut of the oscillator to tuned to the harmonic frequency which it is desired to suppress, namely the fourth harmonic. This circuit therefore offers h e'h impedance to the ripple currents. The se s tuned circuit 75, 77 is also tuned. to either the same or some other harmonic frequency and serves to shunt around the space path of the tube 68 current of the frequency to which it lFI tuned and thus to prevent variations of this frequency in the current supply of this tube.

As a means of further preventing ripples in the rectified current, potentials are impressed upon the grids of the rectifier tubes l'iaving' variations of the frequency of the ripples but in an out-cf-phase relation therewith so that the variations of this frequency in the rectified current are substantially eliminated. The means used to impress these potentials upon the grids of the, rectifier tubes comprises the transformer 55. The primary winding 6-1- of this transformer is connected so as to receive potentials corresponding to ripple components of the rectified current. The condensers 65 and 66 permit the passage of the varying components of the rectified current, but prevent the pass age of the direct current components. thus there results in the secondary winding of transformer a corresponding alternating electremotive force having a frequency the same as that of the ripples of the rectified current. The varying electromotive force"; in the circuit connected to the secondary 54 of transformer are impressed across the {l'FlClS an'l filaments of tubes 31, 32-, 4:1. and -12 at a phase opposite to that of the corresponding variations produced in the output circuits of these tubes. The result of this that the variations in the rectified current are substantially eliminated.

Resistance 77 which is also connected in parallel to the output circuit of the rectifier, has a portion of its length included in the grid filament circuit of the rectifiers and by means of the potential drop along this portion of the resistance, a proper average potential may be maintained upon the grids of these tubes. Condenser 61 is connected in shunt to the portion of the resistance mentioned in order to maintain more nearly a constant potential difference thereacross. The amount of resistance included in the grid filament circuit may be varied by means of the variable contact.

A, resistance 35, a portion of which is common to the input and output circuits of tube 15, is connected in series with the space path of tube l across the output circuit of the rectifier b0 and produces by means of the drop inpotential along the portion of its length included in the amplifier input circuit a suitable average polarizing potential upon the grid of tube 15.

A variable resistance 56 connected in shunt to the secondary winding 5-1 of transformer is provided to enablethe voltage of the transformer to be adjusted with respect to that of transformer 18 in order that ripple variations impressed upon the grid of rectifier modulator tubes may also be suppressed.

Oscillations are generated in the oscillator 40, which is of a well known type. A. resistance 81 connected in series with the resonant circuit 86 is designed to prevent singing. The condenser 82 connected in series with this resistance prevents the flow of current leal-in; from the grid of tube 68 through the resonant circuit 86. Resistance 69 constitutes a grid leak path between the filament and grid of this tube. The reactance of the choke coil 70 prevents the flow of oscillator current in this circuit. Condenser cm nectcd in the lead between resonant circuit 89 and the plate of tube 68 prevents the passsage of direct current from the rectifier through the resonant circuit. Choke coil 72 together with coil 70 prevents the passage of oscillatory current of the frequency generated by the oscilhitor 40 from traversing; the output circuit of the rectifier 30.

The varying current produced by microphone 10 causes variations in the potential of the grid of tube 15. These potential variations control the impedance of the space path of this tube, whereby corresponding: variations in the flow of current in the circuit connected thereto are produced. Similar variations in the potentials applied to the grids of the rectifier modulator tubes are produced by means of the transformer 18. Consequently, the amplitudes of the voltages produced across the filaments and plates of these tubes are modified in accordance with the signals. These potentials are impressed upon the filament-plate circuit of tube 68 such manner as to cause the amplitude of oscillations generated in the system to be varied accordingly. Energy having signal modulations is thus transmitted to antenna 45 from which it is radiated.

circuit. The scope of this invention is only as limited as defined by the appended claims.

lVhat is claimed is:

1. The method of producing speech varied rectified current from a phirality of phases o't alternating current by means of space dis charge devices having main discharge el trodes and control elements, which com n'iscl variably rectifying in accordance with speech a plurality ot phases of said current, combining the rectified current, separating out therefrom undesired ripple variatioi'is, and impressing said ripple variations upon said control elements in ripple neutralizing phase relation.

2. In an electric energy translation system, a source of two-phase (an-rent, space dis-- charge rectifier ionnected to said source, space discharge amplifier and an oscillator supplied With current from said rectificr, and means for eliminating harmonics from said current, said. means comp ing an anti-resonant circuit tuned to a. harmonic frequency in series With said oscillator and a series resonant circuit in shunt thereto.

3. An electric energy translation system which comprises a source of signals, an amplifier cont-rolled by said sis als, a modulator comprising vaciunn tubes syunmetrical 'ly connected to a source of polyphase current connected to said amplifier, an oscillator controlled by said modulator, said oscillator being coupled to a transmitting conductor and a transformer traversed by current tram said modulator and said amplifier for impressing potentials on the grids of said modulator to produce signal modulations and to suppress ripples in the current therefrom.

4:. In a modulating system aspace dis- :harge rectifier connected to a source of polyphase current, a space discharge amplifier connected to a source of signals, and aspace discharge oscillator coupled to an antenna, said amplifier and oscillator having certain oit' their circuits connected mutually in paral lel, means for heating the filaments oi? said space discharge devices from a common source of polyphase current, and; means coupled to said amplifier and to said oscillator for ofifering high impedance to harmonics resulting from the use of polyphase current.

5. A modulator Which comprises a plurality of three electrode space discharge devices having a common input circuit and a common output circuit, a source of pgralphase current connected to said output circuit, means in said input circuit to impress potentials on the grids oi said devices to compensate for harmonic variations in the current in said output circuit, and additional means in said output circuit to selectively impede harmonic variations in the current flowing therein. 7

6. A modulator which comprises a space discharge rectifier, input and output circuits there-tor, a source of two-phase current connected to said rectifier, means in said input circuit to impress potentials corresponding to signal variations on control electrodes of said rectifier, and additional means in said input circuit to impress harmonic variations ot potential on said grids in out-otphase relation to similar harmonic variations of current in said output circuit whereby said variations of current are substantially eliminated.

'2. In a modulating system, a rectifier for tivo-phase electric currents, a source of signals arranged to control. the energy output of said rectifier, an oscillator supplied with current from said rectifier, and means for suppressing ripples in the current supplied to the oscillator, said means comprising a o. later and a series resonant circuitin shunt to said oscillator.

S. In a modulating system, a vacuum tube rectifier, having grid and plate electrodes, ii gut and output circuits connected to the grid and plate electrodes respectively of said rectifier, means for impressing signal variations on said input circuit, and means traversed by varying components of current in said output circuit to impress, additional variations on said input circuit-180 out of phase with the variation in said output circuit whereby the latter variations are substantially eliminated.

9. In a modulating system, a source of signals a source of oscillations and a rectifier connected to a plurality of phases of current for supplying energy to said source of oscillations, and means for suppressing from said rectified current the harmonics. or multiple frequency Whose ordinal is equal to the number of phases, said means comprising a transformer in an input circuit of said. rectifier,- and a plurality of resonant circuits in an output circuit thereof.

10. In an electric Wave transmission systeima source of signals and a source of oscillations, an antenna supplied with energy of said oscillations, a vacuum tube device for rectifying polyphase currentas thesource'ot supply of energy'tor said oscillations said vacuum tube device being controlled by said air a transformer having its primary connected to the output circuit of said rectitying device, and a plurality of resonant circuits connected to said output circuit for allel resonant circuit in series With said eliminating ripples in the current supplied in the rectified current, and means traversed by said rectified current for independently impressing a polarizing potential on the grid electrodes of said amplifier and said rectifier.

12. in a rectifying system, a source of polyphase electric current, a plurality of discharge tubes at least one to each phase, connected to said source, means connected to said source for impressing a polarizing potential on the grids of said discharge tubes, means connected to said source for supplying heating current to the filaments ot said. tubes, and means for applying potentials to the grids of said tubes to compensate for harmonics in the rectified current.

13. In an electric Wave transmission sys tem, a source of two-phase current, a discharge tube rectifier having an output circuit and control circuit connected to said source, a discharge tube amplifier and an oscillator supplied with current from said recti. ier, and means tor eliminating harmonics from said current, said means comprising a discharge tube amplifier having its input circuit connected to the output circuit of said rectifier and having its output circuit connected to said control circuit.

In a rectifier, a source of polyphase electric current, a plurality of discharge tubes having grid, plate and filament electrodes symmetrically connected to said source, said tubes having a common input circuit conn -cted to said grids and a common output circuit connected to said plate electrodes, and means controlled by the variable component of current in said output circuit connected to said input circuit for substantially elimi nating said variable component of current.

15. in a modulating system a source of signals, a. polyphase rectifier controlled by said source, a discharge tube oscillator supplied with current from said rectifier and a variable grid leak i'or said oscillator comprising the space path of a discharge tube to compensate tor harmonics in the rectified current.

16. In an electric energy translation system a vacuum tube rectifier tor polyphase current, an oscillator supplied with current .trom sai d rectifier, said oscillator having a grid or control element and means connected to the control element of said oscillator to impress harmonic potential thereon in out et-phase.

rear/see relation to similar harmonics in the rectified. current, said means comprising a three electrode vacuum tube having its control element connected to the output circuit or" said rectifier.

17. in combination, a space discharge device, means for supplying alternating current to said device, a second space discharge device, means, tor supplying to said second device, alternating current of di li' erent phase from that supplied to said first mentioned device. a common input circuit and a common output circuit for said devices, and means for coupling said circuits including an adjustable resistance.

38. In a rectifying system, a plurality of pace cischarge tubes connected to a poly- ;hase source 01 current, means for heating 'he filaments of said tubes from said source, a space dischar 'e oscillator supp 'ed with current from said rectifier, and means (303% prising a resistance and a plurality oi. condensers, one ott said condensers and a portion oi. said resistance being connected in common in the input and output circuits of sci d rectifier whereby ripples in the rectified current are substantially eliminated.

19. In a radio transmitting system, a source of signals, a full Wave pol phase reci' ificr including a plurality of three electrode soace discharge tubes, a common input circuit con nected to control electrodes and a common output circuit connected to anodes of said tubes, a space discharge repeat r including electrodes having the space patn there: cluded in said output circuit, sain source o signals being coupled to said input circ and means, coinprisingan aperiodic included in both said input and output cuits for eliminating rip 20. In a modulating system signals, a polyphase recfi plurality of space dischare' devices h..vin input and output circuits, loar plied with energy from sail rectifier, and means tor suppressing ripples in the rectified current con'iprisinp' in'ipedance connected directly in shunt to ti e load circuit, less than all. of said impeoance being connected in said input circuit.

In Witness Whereot, l hereunto subscribe my name this 30th day of November A. D., 1923.

circuit sup ARVID 

